Bladder dams OK'd at Pawtucket Falls in Lowell

By Lyle Moran, lmoran@lowellsun.com

Updated:
04/19/2013 06:36:48 AM EDT

Currently flood control atop Lowell's Pawtucket Dam is handled by pieces of plywood attached to iron pipes, both of which are visible in this courtesy photo. A long-awaited decision by the federal government now means this system will be replaced with an electronically-controlled bladder system.

LOWELL -- The inflatable bladder dam is all but certain to come to Lowell after the Pawtucket Dam's owner on Thursday flowed over its biggest federal hurdle to replacing the wooden flashboard system on the Merrimack River.

The Federal Energy Regulatory Commission dealt Boott Hydropower Inc. a major victory with its order approving Boott's application to install a pneumatic crest-gate system which uses metal gates controlled by inflatable rubber bladders to control water flow.

In issuing its ruling approving the license amendment Boott sought in 2010, FERC dismissed the concerns of opponents, including that a crest-gate system at the Pawtucket Falls would negatively impact the historic dam and increase the risk of flooding to nearby areas.

An example of an inflatable bladder dam atop a dam in Northern Vermont like the type approved by the Federal Energy Regulatory Commission for Lowell's Pawtucket Dam.
Courtesy photo

"We find that the proposed pneumatic crest-gate system can be installed without unacceptably altering the dam or adversely affecting the park and historic districts," FERC wrote. "The crest-gate system will also provide important benefits to recreation, fish passage, dam and worker safety, and project generation, and will help alleviate upstream backwater and flooding effects to the maximum extent possible."

Construction of the crest-gate system must begin within two years from the issuance of the order and construction must be complete within four years, according to FERC's decision.

Victor Engel, the vice president of engineering and construction for Enel Green Power North America, Boott Hydropower's parent company, said he was thrilled with FERC's ruling, which he called "a very significant step forward for the project.

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"We are quite pleased FERC has agreed in whole with our proposal and what we have been telling people all along," Engel said. "This project is a win-win for the environment and for the people of Lowell."

Engel said before the $6 million project begins Boott must secure dredge-and-fill permits from the U.S. Army Corps of Engineers and obtain any applicable local permits.

He estimates the project will start either late this year or sometime in 2014.

Engel said it will take 2-3 years to complete the project, which will mean the removal of the wooden flashboards that are designed to fail when river levels get too high or its flow gets too fast.

FERC's ruling comes despite opposition to the crest-gate proposal from the Department of Interior, National Park Service, the federal Advisory Council on Historic Preservation, the Lowell City Council and members of the city's Pawtucketville neighborhood, as well as other opponents.

The dam, which has been around more than 170 years, is part of the Lowell National Historical Park and is listed on the National Register of Historic Places.

Peter Aucella, assistant superintendent of the Lowell National Historical Park, was still reviewing FERC's decision when reached early Thursday afternoon and said he would reserve comment until completing his review.

Deb Forgione, chairwoman of the Pawtucketville Citizens Council, slammed FERC's decision Thursday, saying the bladder-dam system will exacerbate flooding in her neighborhood as well as in neighboring communities.

"You can clearly see FERC listened to no one who was a stakeholder directly affected by what happens to the Pawtucket Dam," Forgione said. "What they have done is they have sealed our fate."

She also said Enel has only pursued the project to boost its bottom line from increased hydroelectric power generation and it is disingenuous for the company to say otherwise.

In its decision, FERC determined that the cost of installing the crest-gate system would exceed the value of the increased power generation. It estimated additional power will bring in $310,000 a year and the annualized capital costs will be $956,000.

Engel said the project will provide an economic boost to Enel Green Power, in addition to many other benefits.

Parties have 30 days to appeal FERC's ruling. Forgione said local opponents are reviewing FERC's decision and weighing whether to challenge it.

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